This project provides support for the participation of the Radiation Oncology Division of the University of Puerto Rico in the Radiation Therapy Oncology Group. This organization is constituted by a national group of academic institutions involved in prospective clinical research in radiation therapy of cancer. Study cases are contributed by the University Hospital, the San Juan V.A. Hospital, the San Juan City Hospital, and the Radiotherapy Institute of the Metropolitan Hospital, all of which form part of the academic radiation therapy program. Patients with types of cancer pertinent to the RTOG protocols are evaluated and registered in the different studies. Treatment is administered in accordance with protocol requirements and then they are followed indefinitely. Besides case accession, this program contributes new protocols and supervises the work on those protocols. In addition, this support will permit participation in the Southeastern Cancer Study Group research projects.